Get GFS ensemble weather signals for one or more cities on a given date. Returns model probability of daily high exceeding various thresholds, derived from the 31-member GFS ensemble forecast. Requires cities (list of city names) and forecast_date (YYYY-MM-DD). Optional: threshold_f (temperature ...
Single-target operation
Part of the Nephyr Weather MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents call get_weather_signals to retrieve information from Nephyr Weather without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though get_weather_signals only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
tools:
get_weather_signals:
rules:
- action: allowSee the full Nephyr Weather policy for all 5 tools.
Agents calling read-class tools like get_weather_signals have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.
Get GFS ensemble weather signals for one or more cities on a given date. Returns model probability of daily high exceeding various thresholds, derived from the 31-member GFS ensemble forecast. Requires cities (list of city names) and forecast_date (YYYY-MM-DD). Optional: threshold_f (temperature threshold, default 70), direction (above/below, default above), market_type (high/low/rain, default high).. It is categorised as a Read tool in the Nephyr Weather MCP Server, which means it retrieves data without modifying state.
Add a rule in your Intercept YAML policy under the tools section for get_weather_signals. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Nephyr Weather MCP server.
get_weather_signals is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the get_weather_signals rule in your Intercept policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the Intercept policy for get_weather_signals. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
get_weather_signals is provided by the Nephyr Weather MCP server (nephyr-weather). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic policy on every MCP tool call. Per-identity grants. Full audit log.